1 00:00:02,740 --> 00:00:03,480 Hate everyone. 2 00:00:03,520 --> 00:00:08,410 Mark Price your debt slopes dot com and today we're going to talk about version control specifically 3 00:00:08,470 --> 00:00:09,720 about get. 4 00:00:10,000 --> 00:00:12,930 So let's get started. 5 00:00:12,940 --> 00:00:16,040 What I'm going to show you is kind of how version control works. 6 00:00:16,300 --> 00:00:24,040 And I want to give you a tip from now on in here into the far future as your development career progresses. 7 00:00:24,310 --> 00:00:28,980 If you are not using version control on every single project you are doing it wrong. 8 00:00:29,080 --> 00:00:34,410 OK I don't want to ever see you creating a project that doesn't have rigid control in some form or fashion. 9 00:00:34,490 --> 00:00:34,800 OK. 10 00:00:34,810 --> 00:00:35,550 That is the law. 11 00:00:35,560 --> 00:00:37,560 Put it in right now in your brain. 12 00:00:37,630 --> 00:00:39,920 Always always always use version control. 13 00:00:40,090 --> 00:00:40,990 OK. 14 00:00:41,410 --> 00:00:44,260 Not to be confused with birth control or things like that. 15 00:00:44,260 --> 00:00:46,460 This is actually really important. 16 00:00:46,660 --> 00:00:50,350 So what is birth control. 17 00:00:50,690 --> 00:00:52,200 Well let's talk about code here. 18 00:00:52,210 --> 00:00:56,220 OK so you write code and exchange programs. 19 00:00:56,260 --> 00:00:58,090 So let's talk about a document. 20 00:00:58,180 --> 00:00:59,710 Let's say we've got this document here. 21 00:00:59,820 --> 00:01:00,290 OK. 22 00:01:00,340 --> 00:01:01,530 It's an ugly document. 23 00:01:01,540 --> 00:01:02,460 It's OK. 24 00:01:02,950 --> 00:01:04,460 This is your document. 25 00:01:05,030 --> 00:01:09,910 OK you've written some code on it and actually it doesn't you have to be code it could be anything could 26 00:01:09,910 --> 00:01:12,690 be a text or whatever but we're going to talk about code. 27 00:01:12,700 --> 00:01:14,510 So you've written some code here. 28 00:01:14,690 --> 00:01:15,490 OK. 29 00:01:15,940 --> 00:01:20,010 Now if you're only one person and if you're working by yourself that's fine. 30 00:01:20,050 --> 00:01:23,750 You keep making changes to this and no one cares right. 31 00:01:23,760 --> 00:01:26,380 You just keep adding and changing it all that you want. 32 00:01:26,380 --> 00:01:32,430 How ever what happens if maybe somewhere right here you broke something. 33 00:01:32,710 --> 00:01:33,570 OK. 34 00:01:34,000 --> 00:01:41,300 And then now your 5000 lines later today 5000 lines later of code and you just realized you had a big 35 00:01:41,380 --> 00:01:42,050 bug. 36 00:01:42,370 --> 00:01:43,170 OK. 37 00:01:43,390 --> 00:01:47,290 Well now you have to dig through 5000 lines of new code to go back and find this coding. 38 00:01:47,290 --> 00:01:48,360 So this is a problem. 39 00:01:48,370 --> 00:01:51,670 You've just done a lot of work and now you're going to have to do a lot more work to find this bug and 40 00:01:51,670 --> 00:01:52,410 go back. 41 00:01:52,600 --> 00:01:53,280 OK. 42 00:01:53,470 --> 00:01:54,400 This is one problem. 43 00:01:54,400 --> 00:01:57,580 Version control can solve and I'll tell you how to solve it in a second. 44 00:01:57,790 --> 00:01:59,260 Here's the next problem. 45 00:01:59,410 --> 00:02:03,980 OK you've got a few people let's just say to people happy Sam here. 46 00:02:04,120 --> 00:02:06,030 OK that's happy Sam. 47 00:02:06,130 --> 00:02:13,200 And this one is beady eyed puppy and he's never really happy. 48 00:02:13,440 --> 00:02:14,210 OK. 49 00:02:14,350 --> 00:02:20,060 So you've got two people here this is Pete this is Sam and they've got their own code files right. 50 00:02:20,320 --> 00:02:22,470 But they're working on the same project. 51 00:02:23,100 --> 00:02:23,760 OK. 52 00:02:24,100 --> 00:02:28,240 So let's say that Sam wants to make some changes to the code base. 53 00:02:28,390 --> 00:02:30,550 OK so he he makes changes. 54 00:02:30,660 --> 00:02:30,970 OK. 55 00:02:30,970 --> 00:02:33,330 And then Pete makes his own changes. 56 00:02:33,490 --> 00:02:34,110 OK. 57 00:02:34,330 --> 00:02:38,430 Now here's the question this is the same project or building an app together. 58 00:02:38,440 --> 00:02:41,370 How does Sam get his changes over to Pete. 59 00:02:42,040 --> 00:02:44,650 He's made one two three changes and now he's mid-twentieth you change. 60 00:02:44,650 --> 00:02:45,180 Well sounds like. 61 00:02:45,190 --> 00:02:45,850 OK. 62 00:02:46,180 --> 00:02:50,430 Let's go ahead and load up Dropbox so you know Dropbox you maybe you've done this before. 63 00:02:50,440 --> 00:02:55,080 So draw box and then he handed it over to me like I made some changes. 64 00:02:55,090 --> 00:02:58,810 So Pete now has a new code file so he then opens up the code file. 65 00:02:58,810 --> 00:03:01,480 So he he opens up this code file here. 66 00:03:02,050 --> 00:03:06,190 And then what he does is he grabs the changes he finds all the changes that were made and then he puts 67 00:03:06,190 --> 00:03:07,520 them here in his code. 68 00:03:07,720 --> 00:03:09,660 OK. 69 00:03:09,790 --> 00:03:12,760 And he mixes them in and he's like OK I put your changes in the code. 70 00:03:12,760 --> 00:03:18,170 Now now I need to give you the latest Fosset MP sends over the combination back to Sam. 71 00:03:18,490 --> 00:03:22,110 OK here's the new file with all of Sam and these changes in it. 72 00:03:22,120 --> 00:03:25,470 And then that's going to go ahead and overwrite this. 73 00:03:25,990 --> 00:03:31,140 And then if you've got a third person here let's say pointy nosed. 74 00:03:31,360 --> 00:03:39,570 Sally joins the project on her B-D angry eyes. 75 00:03:39,610 --> 00:03:41,340 She will go up on the wrong side of the bed. 76 00:03:41,500 --> 00:03:43,410 So she now joins the project. 77 00:03:43,600 --> 00:03:50,110 So now you've got people transferring code OK to all the different players on the team. 78 00:03:50,110 --> 00:03:51,720 Does that make sense. 79 00:03:51,720 --> 00:03:52,800 And we've got this big mess. 80 00:03:52,810 --> 00:03:54,010 Who has the latest version. 81 00:03:54,020 --> 00:03:54,760 Blah blah blah blah. 82 00:03:54,760 --> 00:03:58,030 That's that's how it used to be a long time ago a long time ago. 83 00:03:58,180 --> 00:03:59,610 Do you think that's effective. 84 00:03:59,850 --> 00:04:01,270 Oh that's terrible. 85 00:04:01,270 --> 00:04:02,410 This is all bad. 86 00:04:02,530 --> 00:04:05,810 KATE PLUS you're manually taking these changes inserting them. 87 00:04:05,850 --> 00:04:06,970 Oh it's nasty. 88 00:04:06,980 --> 00:04:08,800 So this is not what we want to do. 89 00:04:08,800 --> 00:04:15,340 Problem one is saving your files if you have problems going back and be unable to revert and find those 90 00:04:15,340 --> 00:04:16,010 issues. 91 00:04:16,210 --> 00:04:23,590 And then you've got this whole issue here with multiple people on the same team DOS version control 92 00:04:23,740 --> 00:04:24,670 was created. 93 00:04:24,900 --> 00:04:25,530 OK. 94 00:04:25,630 --> 00:04:31,150 And what version control is is the controlling of versions of documents. 95 00:04:31,400 --> 00:04:38,320 OK so let's talk about scenario one with your code backup files if someone has used a version control. 96 00:04:38,320 --> 00:04:41,010 Let's go back to Scenario 1 so make a new person here. 97 00:04:41,080 --> 00:04:42,300 Keep it interesting. 98 00:04:42,310 --> 00:04:44,280 This is Jerry. 99 00:04:45,250 --> 00:04:46,920 And Jerry has code. 100 00:04:47,130 --> 00:04:49,620 And now let's say Jerry's using version control. 101 00:04:49,810 --> 00:04:57,250 So he makes change one day to his document and it's saved changed to it's saved. 102 00:04:57,490 --> 00:04:59,630 And we're going to call these actual committees. 103 00:04:59,650 --> 00:05:03,890 That's the that's a phrase that you'll use with version troll especially in regards to get. 104 00:05:04,080 --> 00:05:05,770 So he's making comments right. 105 00:05:06,060 --> 00:05:07,350 So he's committing. 106 00:05:07,980 --> 00:05:12,700 So what he's doing is every time he's making a change he's now committing to version control. 107 00:05:12,850 --> 00:05:18,570 It's being committed Now let's say he comes a version for and he finds a bug here it's like oh my gosh 108 00:05:18,960 --> 00:05:20,120 what's going on here. 109 00:05:20,310 --> 00:05:23,970 Well now what he can do is he can go check out. 110 00:05:23,970 --> 00:05:25,330 It's called checking out. 111 00:05:25,500 --> 00:05:28,340 You know like when you're checking out a girl. 112 00:05:28,540 --> 00:05:30,060 Whatever. 113 00:05:30,570 --> 00:05:33,110 Except in this case you're checking out code. 114 00:05:33,330 --> 00:05:34,380 Not really related. 115 00:05:34,380 --> 00:05:39,360 Anyway he's checking out where he wants to check out a previous commit because he wants to locate worst 116 00:05:39,390 --> 00:05:41,780 problem is what he can do is he can actually check out. 117 00:05:41,910 --> 00:05:43,760 Let's say right here number three. 118 00:05:44,160 --> 00:05:49,290 And then he can run his code his code is restored back to that previous version and he can say OK the 119 00:05:49,290 --> 00:05:50,910 bug still exists here. 120 00:05:51,060 --> 00:05:52,340 So that is not where it happened. 121 00:05:52,350 --> 00:05:57,990 And then he can check out another one another previous commit and he's like OK the bug is gone here. 122 00:05:57,990 --> 00:06:03,990 So then what he can do is he can analyze the differences between those two cochain does he doesn't have 123 00:06:03,990 --> 00:06:06,540 to go back to the 5000 lines of code to find where the problem is. 124 00:06:06,540 --> 00:06:11,040 He can analyze it between the last two changes there where his problem was and let's say that it was 125 00:06:11,040 --> 00:06:11,870 a small problem. 126 00:06:11,940 --> 00:06:15,540 Well he may not want to fix it here he can go back up here but he knows where it is now and then he 127 00:06:15,540 --> 00:06:19,500 can fix that problem or he could just take it out of this altogether. 128 00:06:19,650 --> 00:06:21,920 And then you might have cascading problems down through here. 129 00:06:21,920 --> 00:06:27,810 But regardless the point is you can now easily solve his problem because he can check out previous versions 130 00:06:27,810 --> 00:06:29,090 of his code. 131 00:06:29,100 --> 00:06:32,340 Also this is important here besides just checking our previous code. 132 00:06:32,340 --> 00:06:34,230 This allows you to have multiple versions. 133 00:06:34,320 --> 00:06:36,230 OK multiple versions of your application. 134 00:06:36,270 --> 00:06:37,680 It's like saving backups right. 135 00:06:37,710 --> 00:06:38,410 Saving backups. 136 00:06:38,410 --> 00:06:39,750 That's what this is so this is safe. 137 00:06:39,750 --> 00:06:42,910 This is much better than the first scenario we're talking about. 138 00:06:43,100 --> 00:06:43,880 OK. 139 00:06:44,220 --> 00:06:47,080 Now let's talk about the other scenario where we have multiple people. 140 00:06:47,100 --> 00:06:47,700 OK. 141 00:06:47,850 --> 00:06:50,880 So this guy here so happy. 142 00:06:51,000 --> 00:06:52,100 He loves the code. 143 00:06:52,170 --> 00:06:52,590 All right. 144 00:06:52,620 --> 00:06:54,260 And he's got his code here. 145 00:06:54,990 --> 00:06:56,400 And then let's go over here. 146 00:06:56,820 --> 00:06:59,490 And this guy's name is Sam too. 147 00:06:59,910 --> 00:07:04,070 But this is sinister Sam. 148 00:07:04,320 --> 00:07:09,320 He plays online games and thinks is real cool but I have the handle his code. 149 00:07:09,360 --> 00:07:19,500 And then what we've got down here is you've got this guy and this is Harry and Harry has his own CO-2. 150 00:07:19,920 --> 00:07:21,170 OK how do we solve this problem. 151 00:07:21,180 --> 00:07:24,010 You have any ideas where does version control come into play. 152 00:07:24,090 --> 00:07:25,580 Well let's take a look at this. 153 00:07:25,590 --> 00:07:28,510 So let's say Jim mix changes 1 2 and 3. 154 00:07:29,190 --> 00:07:31,670 And Senator Sam makes changes one to three. 155 00:07:31,780 --> 00:07:33,570 And let's say Harry. 156 00:07:34,000 --> 00:07:37,970 Well Harry sucks at coding so he only made one change and it wasn't really good. 157 00:07:38,400 --> 00:07:43,300 And anyway so you've got these three these three people here i'm just had no one sucks. 158 00:07:43,300 --> 00:07:45,270 Coney's practice you get better over time. 159 00:07:45,630 --> 00:07:49,100 And you're like thanks for de-motivating me. 160 00:07:49,130 --> 00:07:50,310 So they've all made their changes right. 161 00:07:50,310 --> 00:07:53,200 Remember how before we had to swap documents all that kind of stuff. 162 00:07:53,200 --> 00:07:57,540 Well now what we can do is Jim can now commit. 163 00:07:57,610 --> 00:08:00,480 OK so he's made these three commits these three commits these treatments. 164 00:08:00,480 --> 00:08:05,610 He can now push them up to a server OK or some location whatever it doesn't matter it's arbitrary. 165 00:08:05,610 --> 00:08:10,630 The location is arbitrary but let's just call this the let's just call this the server for right now. 166 00:08:10,800 --> 00:08:11,400 OK. 167 00:08:11,400 --> 00:08:14,820 So what he can actually do is he can push these changes here. 168 00:08:15,030 --> 00:08:15,910 OK. 169 00:08:15,960 --> 00:08:20,270 And then what happened is that he can actually pull down those changes. 170 00:08:20,410 --> 00:08:22,950 OK so he can recall this kush. 171 00:08:23,040 --> 00:08:25,910 So Jim can push sinister Samkon. 172 00:08:25,970 --> 00:08:31,470 Paul what happens is it's going to pull those changes and what it's going to do is it's going to automatically 173 00:08:31,680 --> 00:08:36,900 inject those changes where they need to go in Sam's code automatically he's going to inject them in 174 00:08:36,900 --> 00:08:37,510 there. 175 00:08:37,680 --> 00:08:42,780 And if there's no conflict meaning if no one edited the same line of code at the same time it's called 176 00:08:42,780 --> 00:08:46,530 a merge conflict we'll talk about that later on in the lessons. 177 00:08:46,530 --> 00:08:50,170 But do you automatically and inject them right in there. 178 00:08:50,530 --> 00:08:51,010 That's cool. 179 00:08:51,040 --> 00:08:51,710 Now that's Pold. 180 00:08:51,720 --> 00:08:57,090 And now with those things merge this is called a merge so centrist that sinister Sam has now merged 181 00:08:57,480 --> 00:08:58,890 those changes merged. 182 00:08:59,010 --> 00:09:04,840 Now what he can do is he can actually push the merge back to the server so the server is now up to date 183 00:09:04,920 --> 00:09:07,280 with Jim's and sinister stamps code. 184 00:09:07,440 --> 00:09:08,600 And now Harry. 185 00:09:08,720 --> 00:09:09,190 OK. 186 00:09:09,270 --> 00:09:11,640 He can actually pull down all of their changes. 187 00:09:11,650 --> 00:09:14,690 So he's polling and it's going to inject them all in here. 188 00:09:14,700 --> 00:09:16,130 Boom boom boom boom. 189 00:09:16,590 --> 00:09:17,210 OK. 190 00:09:17,430 --> 00:09:22,420 And then once those are merged Harry can now push all the changes back up. 191 00:09:22,440 --> 00:09:25,470 And now the server has everyone's code changes. 192 00:09:25,470 --> 00:09:28,080 No one had to swap files in to happen automatically. 193 00:09:28,160 --> 00:09:32,670 The pushing in the polling like I drew it out here but really you could literally if everything worked 194 00:09:32,670 --> 00:09:36,960 out the way it was you could literally major changes pull down someone else's change just merge them 195 00:09:36,960 --> 00:09:43,020 in and push them back and you could do that within a couple of minutes for less seconds even so we went 196 00:09:43,020 --> 00:09:47,160 from this massively crazy process of managing people's code to working automatically. 197 00:09:47,160 --> 00:09:50,800 Everyone's so happy even sewer system is starting to break out somehow. 198 00:09:51,050 --> 00:09:51,650 OK. 199 00:09:51,840 --> 00:09:54,830 Devious smile but because you put a bug in the code. 200 00:09:54,840 --> 00:09:58,610 But anyway so version control very very powerful. 201 00:09:58,650 --> 00:09:59,280 OK. 202 00:09:59,310 --> 00:10:05,490 Never ever ever ever ever write any code any more on any project if you don't have birth control and 203 00:10:05,490 --> 00:10:10,140 of course the most popular version control system right now is called Get g t. 204 00:10:10,170 --> 00:10:17,790 There are other systems suggest mercurial perforce SVM things like that and some larger companies are 205 00:10:17,790 --> 00:10:22,720 still using those but get is blowing away the world right now it's fantastic. 206 00:10:22,860 --> 00:10:24,830 And that's what we're using in these lessons here. 207 00:10:25,110 --> 00:10:27,730 And it's not that hard. 208 00:10:27,810 --> 00:10:30,580 Even a beginner can get up and running with it fairly quick. 209 00:10:30,600 --> 00:10:38,160 So that's version control that's get started to make sense starting to get your brain wrapping around 210 00:10:38,160 --> 00:10:38,860 the concept. 211 00:10:38,890 --> 00:10:44,130 What in the end what I want you to think about is just imagine having multiple versions of a file and 212 00:10:44,130 --> 00:10:47,510 a system that manages that for you so you never have to copy and paste again. 213 00:10:47,640 --> 00:10:52,380 And because the more you have to do copying and pasting the more air prone your code becomes and you 214 00:10:52,380 --> 00:10:54,360 never ever want any code. 215 00:10:54,360 --> 00:10:54,840 So that's it. 216 00:10:54,840 --> 00:11:01,200 Mark Price and Dev slopes does come move forward and remember to get your free life help go to death 217 00:11:01,200 --> 00:11:05,340 slopes dot com and click on the chat room with thousands of students and they're helping each other 218 00:11:05,340 --> 00:11:05,990 out. 219 00:11:06,000 --> 00:11:09,830 Also click on the forums this is where you can search for answers to your coproduct. 220 00:11:09,840 --> 00:11:12,180 You can also post your own issues so head on over now.